One of my friends made the comment "Shadowdark is what you get if you order DCC from wish". Is he wrong? Feels very thin when I looked at it. But the creator seems very inteligent and passionate about it, so theres that. Maybe it needs a few expansion packs...
They're extremely different games, attempting to do different things.
DCC is a game leaning hard into the gonzo flavor of early D&D (a famous early Dragon magazine, or maybe its precuror, The Strategic Review, featured D&D heroes fighting Nazis in tanks), including going with even more crazy dice than most RPGs use, more randomization in play, including rolling on tables to see what spells do each time they're cast, and a philosophy that every monster is a new and unique one. Play is famously brutal and random, with a ton of sword and sorcery flavor and, if played from level 0, as intended, there's a ton of player character death along the way. Goodman Games is a long-established adventure publisher with a very specific flavor of early TSR adventures, stopping before Dragonlance, and the DCC line is all about that tone.
Shadowdark is a 5E D&D chassis with everything that's not delivering an OSR experience chopped away. It runs faster and quicker, with systems that will be familiar to 5E players when they sit down and play. The randomization is mostly on the side of character generation (characters of the same class will typically have different abilities, because they roll randomly for what they get on a class table) and in adventure generation. It has an explicit horror vibe mixed in, and many of the artists in the book are actually from the black metal scene, further giving it a darker and grimmer vibe than the splatterpunk vibe that DCC gets in its darkest moments.
I think your friend is misunderstanding what one of the two games is doing.
